She was in the middle of an exercise workout when a blood clot on her spine suddenly rendered the avid tennis player and aerobics instructor a paraplegic.

"Words can't describe it, it was absolutely traumatic," says Ms Palmer.

"I'll never forget it, as long as I live. You remember what you were, and now what you have left."

Ms Palmer, who suffered a fibrocartilaginous embolism nine years ago, tried to keep up the tennis but soon quit, finding it "a bit demoralising".

She was soon forced to leave her job due to the lack of disability access to her office, which was on the second floor.

But there was one thing that the mother of two refused to surrender - her ability to drive.

School pick-ups and drop-offs, and the weekly trip to football and basketball matches, were a priority.

It would cost a fortune: a new $50,000 station wagon to fit her wheelchair, and at least $1000 for accelerator and brake hand controls.

Luckily, Ms Palmer could afford it. 

But she knows other wheelchair-users who can't afford to modify their vehicles, which she says amounts to a devastating loss of independence.

"Other people struggle. In many cases, they don't have the same income anymore because they can't work like they used to."

The Victorian government is now waiving the cost of car registration for wheelchair users needing hand controls for accelerating and braking.

Drivers will still have to pay the TAC fee, but will save nearly $300 a year.

About 2500 Victorian drivers own vehicles that have been modified to suit a wheelchair user.

It is expected the discount will prompt more people with spinal cord injuries, amputations, or other mobility limiting conditions, to modify their vehicles. This could also include the elderly.

Car conversions can start at roughly $120 for basic steering wheel aids, with the most expensive modifications enabling electric wheelchair users to enter the vehicle and drive from their wheelchair, at a cost of $150,000. This does not include the cost of the car, or other necessary equipment. 

Minister for Roads and Road Safety Luke Donnellan said the change was "long overdue" and "will make a positive impact on the lives of thousands of Victorians living with a disability".

"We know that wheelchair users face significant costs to have vehicles modified – that's why we're cutting rego costs to make it easier for drivers."

Shrin Akhyani, sales and marketing manager at Blue Badge Insurance Australia, which specialises in road users with disabilities, said the cost of modifying a vehicle can exceed the cost of the car itself.

"The most expensive modification we currently have on our books is a gentleman who has a $70 000 car with a quarter of a million dollars worth of modifications," she said.

Chief executive of Spinal Cure, Duncan Wallace, has relied on taxis and buses to commute since injuring his spine and losing movement in his legs in 1984. He cannot afford to modify his car.

"For the majority of wheelchair users who are capable of driving, I think very few of them can afford to do it."

Mr Wallace said people were starting to seek NDIS funding to modify their vehicles, which, along with discounts on car registrations in Victoria, will have enormous benefits for wheelchair-using drivers.

"I would like to think that other states will follow Victoria's lead on this."

- The Age